1. Field of the Invention
The present invention relates to a sheet feeding device and an image forming apparatus, more specifically, to the configuration of a separating portion which separates sheets fed by a sheet feeding roller.
2. Description of the Related Art
Conventionally, an image forming apparatus such as a printer and a copying machine is provided with a sheet feeding device which has a sheet feeding cassette as a sheet storing portion which stacks sheets therein and a sheet feeding portion which separately feeds the sheets stored in the sheet feeding cassette one by one. In such a sheet feeding device, as a separating mechanism which separates the sheets stacked in the sheet feeding cassette one by one, there is e.g., a retard separating mechanism using a feed roller and a retard roller. There is also a separating mechanism which uses a sheet feeding roller which serves as a pickup and feed function and a separating member (a separating roller and a friction pad).
In the separating mechanism, a sheet guide configuration which picks up sheets and conveys the sheets to a separating portion plays an important role to perform stable separation and conveyance. As a proposal about the guide configuration of the separating portion, a roller supporting member which supports the retard roller is provided with a sheet guide which guides the sheets to a nip portion formed between the feed roller and the retard roller (see Japanese Patent Laid-Open No. 11-222330).
In such a conventional sheet feeding device, with the change in the sheet surface height position of the sheets stacked in the sheet feeding cassette, a feeding direction of the sheet fed from the sheet feeding cassette and an angle of a guide surface of the sheet guide is changed. As a result, when the sheets are guided by the sheet guide, resistance force becomes larger and the sheets cannot be conveyed to the nip portion formed between the feed roller and the retard roller
Accordingly, the present invention has been made in view of such circumstances, and provides a sheet feeding device and an image forming apparatus which can stably separate sheets.